When a user uses a terminal, such as a mobile phone, to obtain a service provided by an operator, the terminal generally needs to firstly obtain authentication information provided by the operator for, e.g., registering with a network of the operator. Conventionally, the authentication information is stored in a subscriber identity module (SIM) card, and the user generally needs to insert the SIM card into a SIM card slot in the terminal. The terminal can then obtain the service provided by the operator after reading the authentication information stored in the SIM card and performing an authenticating process with the operator.
Because the terminal needs to reserve the SIM card slot for the SIM card, a certain space on a circuit board of the terminal is occupied, which reduces a number of electronic components that can be integrated on the circuit board and, thus, may limit expansion of the terminal's functions. In addition, an electromagnetic coupling degree between electronic components on the circuit board is increased, and electromagnetic compatibility of the terminal is reduced. Additionally, a size of the terminal may be increased due to the SIM card slot.